The harnessed booster seats that are part of the recall are the Nautilus 3-in-1, Nautilus Elite and Argos.

According to the government, the seven models that Graco isn't recalling despite being asked to do so by the National Highway Traffic Safety Administration are all infant seats. Specifically, they are: Snugride, Snugride 30, Snugride 32, Infant Safe Seat-Step 1, Snugride 35, Tuetonia 35, and Snugride Click Connect 40.

Asked about these models, Graco's spokeswoman said that any customers with those or other car seats can still call and get a new harness buckle sent to them for free.

But the agency criticized Graco in a letter today, saying that the recall excludes seven infant car seat models with the same buckles.

It says the company and the government have received complaints about stuck buckles on those seats -- and that parents have sometimes had to cut harness straps to remove their child.

Graco says its tests found that food or beverages can make the harness buckles sticky and harder to use. A spokeswoman says the rear-facing infant seats aren't being recalled because infants don't get food or drinks on their seats.

She says the company will send replacement buckles to owners of infant seats on request.